Unither Bioelectronics Logs First Piloted Hydrogen VTOL Flight

Unither Bioelectronics, a subsidiary of United Therapeutics, recently announced that its modified Robinson R44 helicopter made its airborne debut on March 27. It was powered by PEM fuel cells and an electric motor, making it the first successful flight of a piloted, hydrogen-powered VTOL.

The company’s hydrogen journey began nearly a decade ago with the goal of developing a zero-emission vertical takeoff and landing (VTOL) aircraft. This would be used to transport its manufactured organs to hospitals for transplant surgeries. To do so, Unither Bioelectronics partnered with Tier 1 Engineering on a set of battery-powered e-R44s. The third-generation aircraft, using a magniX magni250 motor, took a cross-country flight in October 2022.

However, Unither Bioelectronics eventually decided that their e-R44s would not be capable enough to sustain longer missions. They ditched plans to gain a supplemental type certificate (STC) for the electric conversion and began looking for other sustainable power options.

That’s when the company set its sights on hydrogen fuel cells. Developers spent almost two years hammering down specifics before, in May 2024, VP of program management Mikael Cardinal revealed that the prototype’s first hover was “hopefully imminent.”

Now, ten months later, the modified Robinson R44 technology demonstrator has successfully taken to the skies. Its first flight, piloted by Ric Webb out of Quebec’s Roland-Désourdy Airport (ZBM), lasted 3 minutes and 16 seconds. Unither Bioelectronics revealed the achievement at the VFS H2-Aero Symposium in Long Beach, California.

“The importance of this milestone in aviation history cannot be overstated,” Robinson Helicopter Company CEO David Smith stated. He called the sortie “an incredible first step forward in the path to long-range, zero-emission vertical flight."

The technology demonstrator utilizes two low-temperature proton exchange membrane (PEM) fuel cells, a lithium-ion booster battery pack, and a magniX electric motor, replacing the conventional R44’s Lycoming IO-540 engine. A hydrogen fuel tank is mounted beneath the chopper’s tail boom, with two nacelle cooling systems on its sides.

FMI: www.unither.aero